When people suffer from some types of heart arrhythmias, the result may be that blood flow to various parts of the body is reduced. Some arrhythmias may even result in a sudden cardiac arrest (SCA). SCA can lead to death very quickly, e.g. within 10 minutes, unless treated in the interim.
Some people have an increased risk of SCA. People at a higher risk include patients who have had a heart attack, or a prior SCA episode. A frequent recommendation is for these people to receive an implantable cardioverter defibrillator (“ICD”). The ICD is surgically implanted in the chest, and continuously monitors the patient's electrocardiogram (“ECG”). If certain types of heart arrhythmias are detected, then the ICD delivers an electric shock through the heart.
After being identified as having an increased risk of an SCA, and before receiving an ICD, these people are sometimes given a wearable cardioverter defibrillator (“WCD”) system. (Earlier versions of such systems were called wearable cardiac defibrillator (“WCD”) systems) A WCD system typically includes a harness, vest, or other garment that the patient is to wear. The WCD system includes a defibrillator and electrodes, coupled to the harness, vest, or other garment. When the patient wears the WCD system, the external electrodes may then make good electrical contact with the patient's skin, and therefore can help determine the patient's ECG. If a shockable heart arrhythmia is detected, then the defibrillator delivers the appropriate electric shock through the patient's body, and thus through the heart.
A challenge with prior art wearable cardioverter defibrillator (“WCD”) systems is that, to be on the safe side, they shock the patient more times than is necessary—even when the patient is conscious and does not need a shock. In some instances, a patient may use a cancel switch to avert an impending shock, but even having to do that is a disruption, and can result in unwanted attention by others, loss of privacy and dignity, and so on.